The position of a certain airplane during takeoff is given by x=1/2 *bt2, where b = 2.0 m/s2 and t = 0 corresponds to the instant at which the airplane's brakes are released at position x = 0. The empty but fueled airplane has an inertia of 35,000 kg, and the 160 people on board have an average inertia of65 kg.

What is the magnitude of the airplane's momentum 15s after the brakes are released?